1. Field of the Invention
The present invention relates to W—Cu alloy having a homogeneous micro-structure.
2. Description of the Related Art
Because W—Cu alloy has high electric arc resistance, good thermal conductivity, good electric conductivity and thermal expansion coefficient similar to that of Si used for a semiconductor, it is widely used as a material for high voltage electric contact of a contact braker and a material for heat sink of an IC semiconductor. In addition, because W—Cu alloy has high density and great ductility at a high strain rate, it is spotlighted as a material for a military shaped charge liner.
In a method for fabricating W—Cu alloy in accordance with the conventional art, a method for mixing tungsten powders with copper powders, forming the mixture, sintering it to obtain a skeleton and infiltrating copper was disclosed in Korean Patent No. 0127652. However, in the conventional method, as indicated by arrows in FIG. 1, early mixed copper powders are moved into a space among adjacent tungsten powders by a capillary force in sintering process, permeated copper substitute for tungsten, and accordingly W—Cu alloy having a heterogeneous micro-structure (copper rich region) may be fabricated. When W—Cu alloy having a heterogeneous micro-structure is used as a material for high voltage electric contact of a contact braker and a material for heat sink of an IC semiconductor, crack may occur due to abnormal arc generation or partial thermal expansion coefficient difference, and accordingly life-span of a material for high voltage electric contact of a contact braker and a material for heat sink of an IC semiconductor may be greatly reduced.
When, W—Cu alloy having a heterogeneous micro-structure is used for a military shaped charge liner, the heterogeneous micro-structure may be an immediate cause of anisotropic metal jet occurrence when the liner collapses by explosion of explosive. The anisotropy of metal jet may greatly reduce a penetrating force of a shaped charge liner, and accordingly W—Cu alloy fabricated by the conventional method is inappropriate for a shaped charge liner
In order to solve the above-mentioned problem, applicants of the present invention have developed a method for fabricating W—Cu alloy having a homogeneous micro-structure by using tungsten and W—Cu composite powders (in accordance with Korean Patent No. 248S7/2002 instead of tungsten and copper powders). As depicted in FIG. 2, W—Cu alloy fabricated by that method does not have a heterogeneous structure such as a copper rich region, it can show better performance by being used as a material for high voltage electric contact of a contact braker, a material for heat sink of an IC semiconductor and a material for a shaped charge liner in comparison with W—Cu alloy fabricated by the conventional method.